7.5.10 SRFI-11 - let-values

This module implements the binding forms for multiple values
let-values and let*-values. These forms are similar to
let and let* (see section Local Variable Bindings), but they support
binding of the values returned by multiple-valued expressions.

let-values performs all bindings simultaneously, which means that
no expression in the binding clauses may refer to variables bound in the
same clause list. let*-values, on the other hand, performs the
bindings sequentially, just like let* does for single-valued
expressions.